Solid block and random elastomeric copolymers

Abstract

There is disclosed a linear block copolymer comprising at least one triblock I-B-I, wherein I is a block of a polymerized conjugated diene of at least 5 carbon atoms, such as isoprene, and B is a block of a polymer of a conjugated diene, different from that of formula (1), of at least 4 carbon atoms, such as 1,3-butadiene. The B block is selectively hydrogenated, while each of the I blocks retains a sufficient amount of its original unsaturation to vulcanize the copolymer. There is also disclosed an alternative linear block copolymer containing at least one triblock of the first polymer block made from an aryl-substituted olefin, such as styrene, and the conjugated diene used to polymerize the block I, the second middle polymer block of the diene used to polymerize the block B, and the third polymer block which is the same as the first polymer block. In this alternative copolymer, the middle block is also selectively hydrogenated, thereby leaving the terminal polymer blocks with a sufficient amount of double bonds to vulcanize the copolymer. The polymers can be crosslinked or functionalized through the terminal blocks containing the vinyl unsaturation. There are also disclosed random and star-branched block and random copolymers made from the same monomers as the linear block copolymers. Also disclosed are methods of producing and selectively hydrogenating the polymers.